As noted here last year, Polish artist Jan Lenica (1928–2001) was also an animator as well as a celebrated poster designer. Die Nashörner (1964) is an 11-minute condensation of Eugène Ionesco’s Rhinoceros that no doubt works best if you’re familiar with the play but which nevertheless contains some funny moments, especially when “Rhinocerosism” starts to spread. The film is free to download at the Internet Archive.